Divers Alert Network (DAN) created a very nice short paper on how to equalize the pressure in your ear. This is a key issue for all divers, and one that is essential to master. In the paper below DAN addresses four key topics
How Your Ears Respond to Pressure.
10 Tips that Make Equalizing Easier.
How to Deal with Other Ear Problems.
Known as “middle ear squeeze,” barotrauma affects more than 40% of divers at some point, and therefore is the most common medical problem in scuba diving. When a diver descents, it is essential that they equalize the pressure in the gas-filled body spaces in their ear.
As divers we are taught to add air into the middle ear by equalizing the pressure in the middle ear cavity (swallowing, "gulping sounds," etc.). But when we are unable to restore the pressure differential between the middle ear space and ambient water pressure, we get the "squeeze." Training then teaches us that the diver must ascend to equalize the middle ear pressure with the ambient pressure.
Read the PDF from DAN and feel free to share it with any of your friends that are starting their diving adventure. We all remember how painful the "middle ear squeeze" can be when you don't equalize properly, and when you can do it like a reflex it makes diving an amazing adventure
Sources: Otologic Hazards Related to Scuba Diving